What to Do When Outlook Won't Sync or Is Running Slow

If Outlook is loading slowly, not showing new emails, or stuck on "Updating Inbox," this article walks through the most common fixes. These steps apply to Outlook on Windows and Outlook on the Web.

Quick Fixes to Try First

Restart Outlook — close and reopen the app. This clears most temporary sync issues.
Check your internet connection — open a browser and verify a website loads.
Check Microsoft's service status — visit status.office.com to see if there's a known outage.

Outlook on Windows: Not Syncing

Look at the bottom of the Outlook window for a status bar. If it says "Disconnected" or "Working Offline", click Send/Receive in the top menu, then click Work Offline to toggle it off.
If it says "Updating" but never finishes, go to File > Account Settings > Account Settings, select your email account, and click Repair. Follow the prompts.
If the problem persists, try removing and re-adding your account: go to Control Panel > Mail > Email Accounts > Remove, then add it back.

Outlook on Windows: Running Slow

Compact your mailbox data file: Go to File > Account Settings > Data Files, select your account, click Settings, then Compact Now. This can take a few minutes.
Disable add-ins: Go to File > Options > Add-ins. At the bottom, click Go… next to "COM Add-ins" and uncheck any non-essential add-ins.
Reduce cached email range: Go to File > Account Settings > Account Settings, double-click your account, and slide the Mail to keep offline slider to 3 months instead of "All".

Outlook on the Web (Browser)

Go to outlook.office.com and sign in with your RCS credentials.
If the web version works but the desktop app doesn't, the issue is with the installed app — try the repair steps above.
If the web version is also slow, try clearing your browser cache: press Ctrl + Shift + Delete (Windows) and clear cached images/files.
Try a different browser (Chrome, Edge, Firefox) to rule out a browser issue.

After a Password Change

If you recently changed your Office 365 password, Outlook will stop syncing until you update it. A prompt should appear asking for your credentials — enter your new password. If no prompt appears, go to File > Account Settings > Account Settings, select your account, and click Change to update the password.

Still Not Working?

If none of the above steps resolve the issue, contact IT:

📧 itsupport@redlandschristian.org
🎫 acarcs.zendesk.com

Gmail vs. Outlook: Which Account to Use for What at RCS
How to Set Up Two-Factor Authentication (2FA) on a New Phone or Device
Who to Contact When Self-Service Doesn't Work

Contact IT Support

If you continue to experience issues, please reach out to the RCS IT Help Desk:

Submit a ticket through the IT Help Desk Portal
Email: helpdesk@redlandschristian.org

Keywords: outlook, sync, slow, microsoft, email, troubleshoot

RCS Information Technology · IT Help Center